In contrast, when LM1 and LM9 Nfib KO cells were injected orthotopically and the primary tumour removed, we observed a dramatic abrogation of lung metastasis (orthotopic metastasis assay) compared with controls (Fig 2B and C), providing a rationale to focus on the effect of Nfib in breast cancer metastasis. Here, NFIB is linked to breast carcinoma.